Field of the Invention
Embodiments in accordance with the present invention relate generally to photoimageable compositions containing certain oxetane compounds or polymers having such functional groups for forming microelectronic and/or optoelectronic devices and assemblies thereof, and more specifically to compositions encompassing polynorbornene (PNB) polymers having norbornene-type repeating units that exhibit improved mechanical properties.
Description of the Art
Organic polymer materials are increasingly being used in the microelectronics and optoelectronics industries for a variety of applications. For example, the uses for such organic polymer materials include interlevel dielectrics, redistribution layers (RDL), stress buffer layers, chip stacking and/or bonding, leveling or planarization layers, alpha-particle barriers, passivation layers, among others in the fabrication of a variety of microelectronic and optoelectronic devices. Where such organic polymer materials are photosensitive, thus self-imageable, and therefore, offer additional advantage of reducing the number of processing steps required for the use of such layers and structures made therefrom. Additionally, such organic polymer materials enable the direct adhesive bonding of devices and device components to form various structures. Such devices include microelectromechanical systems (MEMS), microoptoelectromechanical systems (MOEMS) and the semiconductor device encompassing a complementary metal oxide semiconductor (CMOS) image sensor dam structure, and the like.
While certain of the currently available organic photosensitive compositions are used in some of the aforementioned applications, there is still a need for organic photosensitive compositions which feature improved mechanical properties especially in such applications as RDL, chip stacking/bonding and CMOS, where organic materials with higher modulus and tensile strength provide better advantages in fabricating the devices.
Accordingly, there is still a need to develop self imageable photosensitive polymer compositions which feature desirable mechanical properties, i.e., featuring higher tensile strength and modulus with no negative effect on percent elongation while maintaining good stress buffer property and also exhibit high photospeed, bond adhesion, improved thermal oxidative stability and most importantly integration into all involved process steps. Also, it is desirable to process such materials in commonly used solvents.